Fibrous web formed on a structured fabric

ABSTRACT

A fibrous web including a fibrous construct having at least one formed surface feature. The surface feature including a topographical pattern reflective of a weave pattern in a fabric used in a papermaking machine having a through-air drying system. The fabric including a single layer of yarns arranged in a repeating weave pattern, each weave pattern including a plurality of warp yarns substantially oriented in a machine direction (MD) defining MD yarns; and a plurality of weft yarns substantially oriented in a cross machine direction (CD) defining CD yarns. The MD yarns each having at least one long float within the weave pattern. Each long float being adjacent to at least one other long float of an MD yarn. The weave pattern being a plain weave apart from the long floats.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a continuation-in-part of U.S. patent application Ser. No.12/847,519, entitled “STRUCTURED FABRIC”, filed Jul. 30, 2010, which isincorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to papermaking, and relates morespecifically to a fibrous web formed on a structured fabric employed inpapermaking.

2. Description of the Related Art

In a conventional papermaking process, a water slurry, or suspension, ofcellulosic fibers (known as the paper “stock”) is fed into a gap betweentwo endless woven wires that travels between two or more rolls. At leastone of the wires are often referred to as a “structured fabric” thatprovides a papermaking surface on the upper surface of its upper runwhich operates as a filter to separate the cellulosic fibers of thepaper stock from the aqueous medium, thereby forming a wet paper web.The aqueous medium drains through mesh openings of the structuredfabric, known as drainage holes, by gravity or vacuum located on thelower surface of the upper run (i.e., the “machine side”) of the fabric.

After leaving the forming section, the paper web is transferred to apress section of the paper machine, where it is passed through the nipsof one or more pairs of pressure rollers covered with another fabric,typically referred to as a “press felt.” Pressure from the rollersremoves additional moisture from the web; the moisture removal is oftenenhanced by the presence of a “batt” layer of the press felt. The paperis then transferred to a dryer section for further moisture removal.After drying, the paper is ready for secondary processing and packaging.

Typically, papermakers' fabrics are manufactured as endless belts by oneof two basic weaving techniques. In the first of these techniques,fabrics are flat woven by a flat weaving process, with their ends beingjoined to form an endless belt by any one of a number of well-knownjoining methods, such as dismantling and reweaving the ends together(commonly known as splicing), or sewing on a pin-seamable flap or aspecial foldback on each end, then reweaving these into pin-seamableloops. A number of auto-joining machines are available, which forcertain fabrics may be used to automate at least part of the joiningprocess. In a flat woven papermakers' fabric, the warp yarns extend inthe machine direction and the filling yarns extend in the cross machinedirection.

In the second basic weaving technique, fabrics are woven directly in theform of a continuous belt with an endless weaving process. In theendless weaving process, the warp yarns extend in the cross machinedirection and the filling yarns extend in the machine direction. Bothweaving methods described hereinabove are well known in the art, and theterm “endless belt” as used herein refers to belts made by eithermethod.

Effective sheet and fiber support are important considerations inpapermaking, especially for the forming section of the papermakingmachine, where the wet web is initially formed. Additionally, thestructured fabrics should exhibit good stability when they are run athigh speeds on the papermaking machines, and preferably are highlypermeable to reduce the amount of water retained in the web when it istransferred to the press section of the paper machine. In both tissueand fine paper applications (i.e., paper for use in quality printing,carbonizing, cigarettes, electrical condensers, and the like) thepapermaking surface comprises a very finely woven or fine wire meshstructure.

In a conventional tissue forming machine, the sheet is formed flat. Atthe press section, 100% of the sheet is pressed and compacted to reachthe necessary dryness and the sheet is further dried on a Yankee andhood section. The sheet is then creped and wound-up, thereby producing aflat sheet.

In an ATMOS™ system, a sheet is formed on a structured or molding fabricand the sheet is further sandwiched between the structured or moldingfabric and a dewatering fabric. The sheet is dewatered through thedewatering fabric and opposite the molding fabric. The dewatering takesplace with airflow and mechanical pressure. The mechanical pressure iscreated by a permeable belt and the direction of air flow is from thepermeable belt to the dewatering fabric. This can occur when thesandwich passes through an extended pressure nip formed by a vacuum rolland the permeable belt. The sheet is then transferred to a Yankee by apress nip. Only about 25% of the sheet is slightly pressed by the Yankeewhile approximately 75% of the sheet remains unpressed for quality. Thesheet is dried by a Yankee/Hood dryer arrangement and then dry creped.In the ATMOS™ system, one and the same structured fabric is used tocarry the sheet from the headbox to the Yankee dryer. Using the ATMOS™system, the sheet reaches between about 35 to 38% dryness after theATMOS™ roll, which is almost the same dryness as a conventional presssection. However, this advantageously occurs with almost 40 times lowernip pressure and without compacting and destroying sheet quality.Furthermore, a big advantage of the ATMOS™ system is that it utilizes apermeable belt which is highly tensioned, e.g., about 60 kN/m. This beltenhances the contact points and intimacy for maximum vacuum dewatering.Additionally, the belt nip is more than 20 times longer than aconventional press and utilizes airflow through the nip, which is notthe case on a conventional press system.

Actual results from trials using an ATMOS™ system have shown that thecaliper and bulk of the sheet is 30% higher than the conventionalthrough-air drying (TAD) formed towel fabrics. Absorbency capacity isalso 30% higher than with conventional TAD formed towel fabrics. Theresults are the same whether one uses 100% virgin pulp up to 100%recycled pulp. Sheets can be produced with basis weight ratios ofbetween 14 to 40 g/m². The ATMOS™ system also provides excellent sheettransfer to the Yankee working at 33 to 37% dryness. A key aspect of theATMOS™ system is that it forms the sheet on the molding fabric and thesame molding fabric carries the sheet from the headbox to the Yankeedryer. This produces a sheet with a uniform and defined pore size formaximum absorbency capacity.

U.S. patent application Ser. No. 11/753,435 filed on May 24, 2007, thedisclosure of which is hereby expressly incorporated by reference in itsentirety, discloses a structured fabric for an ATMOS™ system. The fabricutilizes an at least three float warp and weft structure which, like theprior art fabrics, is symmetrical in form.

U.S. Pat. No. 5,429,686 to CHIU et al., the disclosure of which ishereby expressly incorporated by reference in its entirety, disclosesstructured forming fabrics which utilize a load-bearing layer and asculptured layer. The fabrics utilize impression knuckles to imprint thesheet and increase its surface contour. This document, however, does notcreate pillows in the sheet for effective dewatering of TADapplications, nor does it teach using the disclosed fabrics on an ATMOS™system and/or forming the pillows in the sheet while the sheet isrelatively wet and utilizing a hi-tension press nip.

U.S. Pat. No. 6,237,644 to HAY et al., the disclosure of which is herebyexpressly incorporated by reference in its entirety, disclosesstructured forming fabrics which utilize a lattice weave pattern of atleast three yarns oriented in both warp and weft directions. The fabricessentially produces shallow craters in distinct patterns. Thisdocument, however, does not teach using the disclosed fabrics on anATMOS™ system.

What is needed in the art is an efficient effective single layer fabricweave pattern to be used in a papermaking machine.

SUMMARY OF THE INVENTION

In one aspect, the invention provides a fibrous web including a fibrousconstruct having at least one formed surface feature. The surfacefeature including a topographical pattern reflective of a weave patternin a fabric used in a papermaking machine having a through-air dryingsystem. The fabric including a single layer of yarns arranged in arepeating weave pattern, each weave pattern including a plurality ofwarp yarns substantially oriented in a machine direction (MD) definingMD yarns; and a plurality of weft yarns substantially oriented in across machine direction (CD) defining CD yarns. The MD yarns each havingat least one long float within the weave pattern. Each long float beingadjacent to at least one other long float of an MD yarn. The weavepattern being a plain weave apart from the long floats.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned and other features and advantages of this invention,and the manner of attaining them, will become more apparent and theinvention will be better understood by reference to the followingdescription of embodiments of the invention taken in conjunction withthe accompanying drawings, wherein:

FIG. 1 shows a repeating weave pattern having a square shape of a topside or paper facing side of an embodiment of a structured fabric of thepresent invention, each ‘X’ indicating a location where a warp MD yarnpasses over a weft CD yarn;

FIG. 2 shows the weave pattern of the structured fabric of FIG. 1;

FIG. 3 shows a repeating weave pattern having a square shape of a topside or paper facing side of another embodiment of a structured fabricof the present invention, each ‘X’ indicating a location where a warp MDyarn passes over a weft CD yarn;

FIG. 4 shows the weave pattern of the structured fabric of FIG. 3;

FIG. 5 shows a repeating weave pattern having a square shape of a topside or paper facing side of yet another embodiment of a structuredfabric of the present invention, each ‘X’ indicating a location where awarp MD yarn passes over a weft CD yarn;

FIG. 6 shows the weave pattern of the structured fabric of FIG. 5;

FIG. 7 shows a repeating weave pattern having a square shape of a topside or paper facing side of yet another embodiment of a structuredfabric of the present invention, each ‘X’ indicating a location where awarp MD yarn passes over a weft CD yarn;

FIG. 8 shows the weave pattern of the structured fabric of FIG. 7;

FIG. 9 shows a repeating weave pattern having a square shape of a topside or paper facing side of yet another embodiment of a structuredfabric of the present invention, each ‘X’ indicating a location where awarp MD yarn passes over a weft CD yarn;

FIG. 10 shows the weave pattern of the structured fabric of FIG. 9;

FIG. 11 shows a repeating weave pattern having a square shape of a topside or paper facing side of yet another embodiment of a structuredfabric of the present invention, each ‘X’ indicating a location where awarp MD yarn passes over a weft CD yarn;

FIG. 12 shows the weave pattern of the structured fabric of FIG. 11;

FIG. 13 shows a repeating weave pattern having a square shape of a topside or paper facing side of yet another embodiment of a structuredfabric of the present invention, each ‘X’indicating a location where awarp MD yarn passes over a weft CD yarn;

FIG. 14 shows the weave pattern of the structured fabric of FIG. 13;

FIG. 15 shows a repeating weave pattern having a square shape of a topside or paper facing side of yet another embodiment of a structuredfabric of the present invention, each ‘X’ indicating a location where awarp MD yarn passes over a weft CD yarn;

FIG. 16 shows the weave pattern of the structured fabric of FIG. 15;

FIG. 17 shows a repeating weave pattern having a square shape of a topside or paper facing side of yet another embodiment of a structuredfabric of the present invention, each ‘X’ indicating a location where awarp MD yarn passes over a weft CD yarn;

FIG. 18 shows the weave pattern of the structured fabric of FIG. 17;

FIG. 19 shows a repeating weave pattern having a square shape of a topside or paper facing side of yet another embodiment of a structuredfabric of the present invention, each ‘X’ indicating a location where awarp MD yarn passes over a weft CD yarn;

FIG. 20 shows the weave pattern of the structured fabric of FIG. 19;

FIG. 21 shows a repeating weave pattern having a square shape of a topside or paper facing side of yet another embodiment of a structuredfabric of the present invention, each ‘X’ indicating a location where awarp MD yarn passes over a weft CD yarn;

FIG. 22 shows the weave pattern of the structured fabric of FIG. 21;

FIG. 23 shows a repeating weave pattern having a square shape of a topside or paper facing side of yet another embodiment of a structuredfabric of the present invention, each ‘X’ indicating a location where awarp MD yarn passes over a weft CD yarn;

FIG. 24 shows the weave pattern of the structured fabric of FIG. 23;

FIG. 25 shows a repeating weave pattern having a square shape of a topside or paper facing side of yet another embodiment of a structuredfabric of the present invention, each ‘X’ indicating a location where awarp MD yarn passes over a weft CD yarn;

FIG. 26 shows the weave pattern of the structured fabric of FIG. 25;

FIG. 27 shows a repeating weave pattern having a square shape of a topside or paper facing side of yet another embodiment of a structuredfabric of the present invention, each ‘X’ indicating a location where awarp MD yarn passes over a weft CD yarn;

FIG. 28 shows the weave pattern of the structured fabric of FIG. 27;

FIG. 29 illustrates a schematic cross-sectional view of an embodiment ofan ATMOS™ papermaking machine;

FIG. 30 illustrates a schematic cross-sectional view of anotherembodiment of an ATMOS™ papermaking machine;

FIG. 31 illustrates a schematic cross-sectional view of anotherembodiment of an ATMOS™ papermaking machine;

FIG. 32 illustrates a schematic cross-sectional view of anotherembodiment of an ATMOS™ papermaking machine;

FIG. 33 illustrates a schematic cross-sectional view of anotherembodiment of an ATMOS™ papermaking machine;

FIG. 34 illustrates a schematic cross-sectional view of anotherembodiment of an ATMOS™ papermaking machine;

FIG. 35 illustrates a schematic cross-sectional view of anotherembodiment of an ATMOS™ papermaking machine;

FIG. 36 illustrates a schematic cross-sectional view of anotherembodiment of an ATMOS™ papermaking machine; and

FIG. 37 is a schematic process flow diagram of a throughdrying processin accordance with this invention, illustrating an uncrepedthroughdrying process with only one throughdryer;

FIG. 38 is a schematic process flow diagram of a throughdrying processin accordance with this invention, illustrating an uncrepedthroughdrying process having two throughdryers in series; and

FIG. 39 shows another schematic view of an apparatus for practicing thepresent invention product and process.

Corresponding reference characters indicate corresponding partsthroughout the several views. The exemplification set out hereinillustrates one embodiment of the invention, in one form, and suchexemplification is not to be construed as limiting the scope of theinvention in any manner.

DETAILED DESCRIPTION OF THE INVENTION

The particulars shown herein are by way of example and for purposes ofillustrative discussion of the embodiments of the present invention onlyand are presented in the cause of providing what is believed to be themost useful and readily understood description of the principles andconceptual aspects of the present invention. In this regard, no attemptis made to show structural details of the present invention in moredetail than is necessary for the fundamental understanding of thepresent invention, and the description is taken with the drawings makingapparent to those skilled in the art how the forms of the presentinvention may be embodied in practice.

The present invention relates to a structured fabric for a papermakingmachine, a former for manufacturing a paper web, and also to a formerwhich utilizes the structured fabric, and in some embodiments a beltpress, in a papermaking machine.

The present invention also relates to a twin wire former ATMOS™ systemwhich utilizes the structured fabric which has good resistance topressure and excessive tensile strain forces, and which can withstandwear/hydrolysis effects that are experienced in an ATMOS™ system. Thesystem may also include a permeable belt for use in a high tensionextended nip around a rotating roll or a stationary shoe and adewatering fabric for the manufacture of premium tissue or towel grades.The fabric has key parameters which include permeability, weight,caliper, and certain compressibility.

The structured fabric of the present invention is illustrated in FIGS.1-28. FIG. 1 depicts a weave pattern 10 from a top pattern view of theweb facing side of the fabric (i.e., a view of the papermaking surface).The numbers 1-20 shown on the bottom of the pattern identify the warp,machine direction (MD) yarns while the right side numbers 1-20 show theweft, cross-direction (CD) yarns. The symbol X illustrates a locationwhere a warp yarn passes over a weft yarn and an empty box illustrates alocation where a warp yarn passes under a weft yarn. As shown in FIG. 1,the areas that are shaded indicate long float warp yarns, which floatover at least two weft yarns. The shaded areas form a MD float pattern,while the non-shaded areas represent a plain weave pattern. In a likemanner the weave patterns of FIGS. 3, 5, 7, 9, 11, 13, 15, 17, 19, 21,23, 25, and 27 illustrate other embodiments of the present invention.

FIG. 2 illustrates the weave pattern of the MD yarns relative to the CDyarns with the CD yarns being represented in each line as the numbers,with the line being the pattern of the MD yarn. Each line representingthe MD yarn identified along the left side of the Fig. In a like mannerFIG. 4 corresponds to FIG. 3 and so on with the even numbered figuresthrough FIG. 28, corresponding to the odd numbered figure that isnumerically one less than the even numbered Fig.

The embodiments shown in FIGS. 1-28 are illustrative of the inventionand the invention is not limited to the weave patterns shown therein.

The fabric of FIGS. 1-28 illustrates a repeating weave pattern square ofthe fabric that encompasses twenty MD warp yarns (yarns 1-20 numberedalong the bottom of each pattern) and twenty weft yarns (yarns 1-20 thatare numbered along the right side of each pattern). There are longfloats of the MD warp yarns over the weft yarns, with the long floatbeing over at least two weft yarns, and in most patterns over at leastthree weft yarns. Although in some patterns the MD warp yarn float isover at least four or even over at least five weft yarns.

Where the MD warp yarns have there long float they are always adjacentto at least one other MD warp yarn that is also undergoing a long float.The float beginning and ending are offset in the MD by one weft yarnposition. The contiguous adjacent MD warp yarns form an MD yarn floatpattern, with at least one being present in each weave pattern 10. TheMD yarn float patterns are replicated in weave pattern 10, and includesminor-image or reflected MD yarn float patterns. The MD yarn floatpatterns can be symmetrical or asymmetrical. For example, in FIG. 1there is one MD yarn float pattern having a float over five weft yarnsthat is only four MD yarns wide and there is another MD yarn floatpattern having a float over five weft yarns that is five MD yarns wide.So, while the patterns are similar and are a reflection of each other,they are also asymmetrical.

Looking at FIG. 3, there are MD yarn float patterns that aremirror-images and are symmetrical. The MD yarns float over three weftyarns and are three MD yarns wide. In each case apart from the MD yarnfloat patterns the weave of the single layer fabric is a simple weavepattern. In many cases the plain weave pattern surrounds the MD yarnfloat patterns. In some weave patterns, such as those of FIGS. 17 and19, the simple weave patterns appear surrounded by MD yarn floatpatterns.

The parameters of the structured fabric shown in FIGS. 1-28 can have amesh (number of warp yarns per inch) and a count (number of weft yarnsper inch) of any amount. The single-layered fabric should have a highpermeability value due to the nature of a single layer fabric and theway it is woven. Regarding yarn dimensions, the particular size of theyarns is typically governed by the mesh of the papermaking surface andthe yarn size can be selected based upon the intended use. Fabricsemploying these yarn sizes may be implemented with polyester yarns orwith a combination of polyester and nylon yarns.

The structured fabric can also be treated and/or coated with anadditional polymeric material that is applied by, e.g., deposition. Thematerial can be added cross-linked during processing in order to enhancefabric stability, contamination resistance, drainage, wearability,improve heat and/or hydrolysis resistance and in order to reduce fabricsurface tension. This aids in sheet release and/or reduced drive loads.The treatment/coating can be applied to impart/improve one or several ofthese properties of the fabric. As indicated previously, thetopographical pattern in the paper web can be changed and manipulated byuse of different single-layer weaves. Further enhancement of the patterncan be attained by adjustments to the specific fabric weave by changesto the yarn diameter, yarn counts, yarn types, yarn shapes,permeability, caliper and the addition of a treatment or coating etc. Inaddition, a printed design, such as a screen-printed design, ofpolymeric material can be applied to the fabric to enhance its abilityto impart an aesthetic pattern into the web or to enhance the quality ofthe web. Finally, one or more surfaces of the fabric or molding belt canbe subjected to sanding and/or abrading in order to enhance surfacecharacteristics.

The characteristics of the individual yarns utilized in the fabric ofthe present invention can vary depending upon the desired properties ofthe final papermakers' fabric. For example, the materials comprisingyarns employed in the fabric of the present invention may be thosecommonly used in papermakers' fabric. As such, the yarns may be formedof polypropylene, polyester, nylon, or the like. The skilled artisanshould select a yarn material according to the particular application ofthe final fabric.

By way of non-limiting example, the structured fabric is asingle-layered woven fabric which can withstand high pressures, heat,moisture concentrations, and which can achieve a high level of waterremoval and also mold or emboss the paper web. These characteristicsprovide a structured fabric appropriate for the Voith ATMOS™ papermakingprocess. The fabric preferably has a width stability and a suitable highpermeability and preferably utilizes hydrolysis and/or temperatureresistant materials, as discussed above. The fabric is preferably awoven fabric that can be installed on an ATMOS™ machine as a pre-joinedand/or seamed continuous and/or endless belt. Alternatively, thestructured fabric can be joined in the ATMOS™ machine using, e.g., apin-seam arrangement or can otherwise be seamed on the machine.

The invention also provides for utilizing the structured fabricdisclosed herein on a machine for making a fibrous web, e.g., tissue orhygiene paper web, etc., which can be, e.g., a twin wire+a permeablebelt ATMOS™ system. Referring again to the drawings, and moreparticularly to FIGS. 29-35, there is a fibrous web machine including aheadbox 22 that discharges a fibrous slurry between a forming fabric 26and a structured fabric 28 having a weave pattern 10. It should beunderstood that structured fabric 28 is an embodiment of the structuredfabric discussed above in connection with FIGS. 1-28. Rollers 30 and 32direct fabric 26 in such a manner that tension is applied thereto,against slurry 24 and structured fabric 28. Structured fabric 28 issupported by forming roll 34 which rotates with a surface speed thatmatches the speed of structured fabric 28 and forming fabric 26.Structured fabric 28 has peaks and valleys as defined by weave pattern10, which give a corresponding structure to web 38 formed thereon.Structured fabric 28 travels in a web direction, and as moisture isdriven from the fibrous slurry, structured fibrous web 38 takes form.The moisture that leaves the slurry travels through forming fabric 26.

The fibrous slurry is formed into a web 38 with a structure that matchesthe shape of structured fabric 28. Forming fabric 26 is porous andallows moisture to escape during forming. Further, water is removedthrough dewatering fabric 82. The removal of moisture through fabric 82does not cause compression of web 38 traveling on structured fabric 28.

Due to the formation of the web 38 with the structured fabric 28 thepockets of the fabric 28 are fully filled with fibers. Therefore, at theYankee surface 52 the web 38 has a much higher contact area, up toapproximately 100%, as compared to the prior art because the web 38 onthe side contacting the Yankee surface 52 is almost flat.

Referring to FIG. 29, there is shown an embodiment of the process wherea structured fibrous web 38 is formed. Structured fabric 28 carries athree dimensional structured fibrous web 38 to an advanced dewateringsystem 50, past vacuum box 67 and then to a position where the web istransferred to Yankee dryer 52 and hood section 54 for additional dryingand creping before winding up on a reel (not shown).

A shoe press 56 is placed adjacent to structured fabric 28, holdingfabric 28 in a position proximate Yankee dryer 52. Structured fibrousweb 38 comes into contact with Yankee dryer 52 and transfers to asurface thereof, for further drying and subsequent creping.

A vacuum box 58 is placed adjacent to structured fabric 28 to achieveimproved solids levels. Web 38, which is carried by structured fabric28, contacts dewatering fabric 82 and proceeds toward vacuum roll 60.Vacuum roll 60 operates at a vacuum level of −0.2 to −0.8 bar with apreferred operating level of at least −0.4 bar. Hot air hood 62 isoptionally fit over vacuum roll 60 to improve dewatering.

Optionally a steam box can be installed instead of the hood 62 supplyingsteam to the web 38. The steam box preferably has a sectionalized designto influence the moisture re-dryness cross profile of the web 38. Thelength of the vacuum zone inside the vacuum roll 60 can be from 200 mmto 2,500 mm, with a preferable length of 300 mm to 1,200 mm and an evenmore preferable length of between 400 mm to 800 mm. The solids level ofweb 38 leaving suction roll 60 is 25% to 55% depending on installedoptions. A vacuum box 67 and hot air supply 65 can be used to increaseweb 38 solids after vacuum roll 60 and prior to Yankee dryer 52. Wireturning roll 69 can also be a suction roll with a hot air supply hood.As discussed above, roll 56 includes a shoe press with a shoe width of80 mm or higher, preferably 120 mm or higher, with a maximum peakpressure of less than 2.5 MPa. To create an even longer nip tofacilitate the transfer of web 38 to Yankee dryer 52, web 38 carried onstructured fabric 28 can be brought into contact with the surface ofYankee dryer 52 prior to the press nip associated with shoe press 56.Further, the contact can be maintained after structured fabric 28travels beyond press 56.

Now, additionally referring to FIG. 30, there is shown yet anotherembodiment of the present invention, which is substantially similar tothe invention illustrated in FIG. 29, except that instead of hot airhood 62, there is a belt press 64. Belt press 64 includes a permeablebelt 66 capable of applying pressure to the machine side of structuredfabric 28 that carries web 38 around vacuum roll 60. Fabric 66 of beltpress 64 is also known as an extended nip press belt or a link fabric,which can run at 60 KN/m fabric tension with a pressing length that islonger than the suction zone of roll 60.

Preferred embodiments of the fabric 66 and the required operationconditions are also described in PCT/EP2004/053688 and PCT/EP2005/050198which are herewith incorporated by reference.

The above mentioned references are also fully applicable for dewateringfabrics 82 and press fabrics 66 described in the further embodiments.

Belt 66 is a specially designed extended nip press belt 66, made of, forexample reinforced polyurethane and/or a spiral link fabric. Belt 66also can have a woven construction. Such a woven construction isdisclosed, e.g., in EP 1837439. Belt 66 is permeable thereby allowingair to flow there through to enhance the moisture removing capability ofbelt press 64. Moisture is drawn from web 38 through dewatering fabric82 and into vacuum roll 60.

Referring to FIG. 31, there is shown another embodiment of the presentinvention which is substantially similar to the embodiment shown in FIG.30 with the addition of hot air hood 68 placed inside of belt press 64to enhance the dewatering capability of belt press 64 in conjunctionwith vacuum roll 60.

Referring to FIG. 32, there is shown yet another embodiment of thepresent invention, which is substantially similar to the embodimentshown in FIG. 30, but including a boost dryer 70 which encountersstructured fabric 28. Web 38 is subjected to a hot surface of boostdryer 70, and structured web 38 rides around boost dryer 70 with anotherwoven fabric 72 riding on top of structured fabric 28. On top of wovenfabric 72 is a thermally conductive fabric 74, which is in contact withboth woven fabric 72 and a cooling jacket 76 that applies cooling andpressure to all fabrics and web 38. The pressing process does notnegatively impact web quality. The drying rate of boost dryer 70 isabove 400 kg/hr m² and preferably above 500 kg/hr m². The concept ofboost dryer 70 is to provide sufficient pressure to hold web 38 againstthe hot surface of the dryer thus preventing blistering. Steam that isformed at the knuckle points of fabric 28 passes through fabric 28 andis condensed on fabric 72. Fabric 72 is cooled by fabric 74 that is incontact with cooling jacket 76, which reduces its temperature to wellbelow that of the steam. Thus the steam is condensed to avoid a pressurebuild up to thereby avoid blistering of web 38. The condensed water iscaptured in woven fabric 72, which is dewatered by dewatering device 75.It has been shown that depending on the size of boost dryer 70, the needfor vacuum roll 60 can be eliminated. Further, depending on the size ofboost dryer 70, web 38 may be creped on the surface of boost dryer 70,thereby eliminating the need for Yankee dryer 52.

Referring to FIG. 33, there is shown yet another embodiment of thepresent invention substantially similar to the invention disclosed inFIG. 30 but with an addition of an air press 78, which is a four rollcluster press that is used with high temperature air and is referred toas a High Pressure Through Air Dryer (HPTAD) for additional web dryingprior to the transfer of web 38 to Yankee dryer 52. Four-roll clusterpress 78 includes a main roll, a vented roll, and two cap rolls. Thepurpose of this cluster press is to provide a sealed chamber that iscapable of being pressurized. The pressure chamber contains hightemperature air, for example, 150° C. or higher and is at asignificantly higher pressure than conventional TAD technology, forexample, greater than 1.5 psi resulting in a much higher drying ratethan a conventional TAD. The high-pressure hot air passes through anoptional air dispersion fabric, through web 38 and fabric structured 28into a vent roll. The air dispersion fabric may prevent web 38 fromfollowing one of the cap rolls. The air dispersion fabric is very open,having a permeability that equals or exceeds that of fabric structured28. The drying rate of the HPTAD depends on the solids content of web 38as it enters the HPTAD. The preferred drying rate is at least 500 kg/hrm², which is a rate of at least twice that of conventional TAD machines.

Advantages of the HPTAD process are in the areas of improved sheetdewatering without a significant loss in sheet quality and compactnessin size and energy efficiency. Additionally, it enables higherpre-Yankee solids, which increase the speed potential of the invention.Further, the compact size of the HPTAD allows for easy retrofitting toan existing machine. The compact size of the HPTAD and the fact that itis a closed system means that it can be easily insulated and optimizedas a unit to increase energy efficiency.

Referring to FIG. 34, there is shown another embodiment of the presentinvention. This is significantly similar to the embodiments shown inFIGS. 30 and 33 except for the addition of a two-pass HPTAD 80. In thiscase, two vented rolls are used to double the dwell time of structuredweb 38 relative to the design shown in FIG. 33. An optional coarse meshfabric may be used as in the previous embodiment. Hot pressurized airpasses through web 38 carried on structured fabric 28 and onto the twovent rolls. It has been shown that depending on the configuration andsize of the HPTAD, more than one HPTAD can be placed in series, whichcan eliminate the need for roll 60.

Referring to FIG. 35, a conventional twin wire former 90 may be used toreplace the crescent former shown in previous examples. The forming rollcan be either a solid or open roll. If an open roll is used, care mustbe taken to prevent significant dewatering through the structured fabricto avoid losing basis weight in the pillow areas. The outer formingfabric 93 can be either a standard forming fabric or one such as thatdisclosed in U.S. Pat. No. 6,237,644. The inner fabric 91 should be astructured fabric that is much coarser than the outer forming fabric 90.For example, inner fabric 91 may be similar to structured fabric 28. Avacuum roll 92 may be needed to ensure that the web stays withstructured fabric 91 and does not go with outer wire 90. Web 38 istransferred to structured fabric 28 using a vacuum device. The transfercan be a stationary vacuum shoe or a vacuum assisted rotating pick-uproll 94. The second structured fabric 28 is at least the same coarsenessand preferably coarser than first structured fabric 91. The process fromthis point is the same as the process previously discussed inconjunction with FIG. 30. The registration of the web from the firststructured fabric to the second structured fabric is not perfect, and assuch some pillows will lose some basis weight during the expansionprocess, thereby losing some of the benefit of the present invention.However, this process option allows for running a differential speedtransfer, which has been shown to improve some sheet properties. Any ofthe arrangements for removing water discussed above as may be used withthe twin wire former arrangement and a conventional TAD.

Referring to FIG. 36 there is illustrated another ATMOS™ system havingmany elements as discussed above. The ATMOS™ system of FIG. 36, isfurther described in WO 2010/069695 having a priority date of Dec. 19,2008. Belt press 64 constitutes a first pressing zone where web 38 ispressed. Web 38 proceeds to a second pressing zone 65 where web 38 ispressed again.

FIGS. 37-39 illustrate types of TAD systems, specifically thosedescribed in the patent record of Kimberly-Clark (See WO 2005/073461 A1)and Procter & Gamble (See WO 2009/069046 A1). FIG. 37 illustrates one ofmany papermaking processes to which the invention is applicable. Shownis an uncreped throughdried tissue process in which a twin wire formerhaving a layered papermaking headbox 205 injects or deposits a stream ofan aqueous suspension of papermaking fibers between two forming fabrics206 and 207. Forming fabric 207 being the same as structured fabric 28,discussed above. Forming fabric 207 serves to support and carry thenewly-formed wet web 208 downstream in the process as the web ispartially dewatered to an appropriate consistency, such as about 10% dryweight percent. As shown in this example, profiling of the web inaccordance with this invention takes place at the point in the processwhere the exhaust gas recovery plenum 211 and the vacuum box(es) 210 arepositioned. Additional dewatering of the wet web can be carried out,such as by vacuum suction, using one or more steam boxes in conjunctionwith one or more vacuum suction boxes (not shown) while the wet web issupported by the forming fabric 207.

The wet web 208 is then transferred from the forming fabric 207 to atransfer fabric 213 traveling at a slower speed than the forming fabric207 in order to impart increased MD stretch into the web. The transferis carried out to avoid compression of the wet web, preferably with theassistance of a vacuum shoe 214. Although not shown, it is within thescope of this invention for the profiling to take place at any pointwhile the web is supported by the transfer fabric as well as the formingfabric 207.

The web is then transferred from the transfer fabric 213 to thethroughdrying fabric 220 with the aid of a vacuum transfer roll 215 or avacuum transfer shoe. Transfer is preferably carried out with vacuumassistance to ensure deformation of the sheet to conform to thethroughdrying fabric, thus yielding desired bulk, flexibility, CDstretch and appearance.

The vacuum shoe (negative pressure) can be supplemented or replaced bythe use of positive pressure from the opposite side of the web to blowthe web onto the next fabric in addition to or as a replacement forsucking it onto the next fabric with vacuum. Also, a vacuum roll orrolls can be used to replace the vacuum shoe(s).

While supported by the throughdrying fabric 220, the web is dried to afinal consistency, typically about 94 percent or greater, by thethroughdryer 225 and thereafter transferred to a carrier fabric 230. Thedried basesheet 227 is transported to the reel 235 using carrier fabric230 and an optional carrier fabric 231. An optional pressurized turningroll 233 can be used to facilitate transfer of the web from carrierfabric 230 to fabric 231. Although not shown, reel calendering orsubsequent off-line calendering can be used to improve the smoothnessand softness of the basesheet.

The hot air used to dry the web while passing over the throughdryer isprovided by a burner 240 and distributed over the surface of thethroughdrying drum using a hood 241. The air is drawn through the webinto the interior of the throughdrying drum via fan 243 which serves tocirculate the air back to the burner. In order to avoid moisturebuild-up in the system, a portion of the spent air is vented 245, whilea proportionate amount of fresh make-up air 247 is fed to the burner.The exhaust gas recycle stream 250 provides exhaust gas to the exhaustgas recovery plenum 211 operatively positioned in the vicinity of one ormore vacuum suction boxes 210, such that exhaust gas fed to the exhaustgas recovery plenum is drawn through the web, through the papermakingfabric and into the vacuum box(es) in order to control the consistencyprofile the web. The humidity of the recycled exhaust gas can be about0.15 pounds of water vapor or greater per pound of air, morespecifically about 0.20 pounds of water vapor or greater per pound ofair, and still more specifically about 0.25 pounds of water vapor orgreater per pound of air.

FIG. 38 is a schematic process flow diagram of another throughdryingprocess in accordance with this invention, similar to that illustratedin FIG. 37, but in which two throughdryers are used in series to dry theweb. The components of the second throughdryer are given the samereference numbers used for the first throughdryer, but distinguishedwith a “prime”. When two throughdryers are used as shown, the exhaustgas from the first (primary) throughdryer is recycled to the exhaust gasrecovery plenum 211 because of its relatively greater heat value. Aspreviously noted, if the throughdryers are operated in such a fashionthat the relative heat value of the second throughdryer is greater thanthe first for the given application, the exhaust gas from the secondthroughdryer can be used for the recycle stream to the exhaust gasrecovery plenum 211.

Optionally, exhaust gas from the second throughdryer can be used to heatand/or profile the dewatered web by providing an exhaust gas recyclestream 255 which, as shown, is directed to exhaust gas recovery plenum256 opposite vacuum roll or shoe 257. Any of the web-contacting orsheet-contacting rolls in the vicinity of vacuum roll or shoe 257 arealso suitable locations for introducing the exhaust gas for purposes ofprofiling in accordance with this invention should these rolls beequipped with vacuum. As an alternative (not shown), a vacuum box can beplaced within the loop of fabric 213 and the plenum 256 can be placedoperatively opposite this vacuum box to profile the web.

As described supra, one fibrous structure useful in achieving thefibrous structure paper product of the present invention is thethrough-air-dried (TAD), differential density structure described inU.S. Pat. No. 4,528,239. Such a structure may be formed according to thenonlimiting embodiment of the apparatus exemplified in FIG. 39. Theapparatus 300 includes a head box 310, a Fourdrinier section 320comprising a Fourdrinier wire 322, a press section 330 comprising a TADcarrier fabric 332, which is the same as structured fabric 28 discussedabove and a Yankee Dryer 340.

In one embodiment, it is possible to operate the papermaking machinesuch that there is a differential velocity between the TAD carrierfabric 332 and the Fourdrinier wire 322 to provide increased fibers inthe pillow regions of the fibrous web. The Fourdrinier wire 322 may evenrun at a higher speed than the TAD carrier fabric 332.

As described supra, it is found that some consumers prefer a relativelybulky product as compared to a relatively cushiony product. It issurprisingly found that in addition to the process/additive changesdescribed supra, in some embodiments during the transfer of the slurryfrom the Fourdrinier wire to the TAD carrier fabric, if the speed of theFourdrinier wire and the speed of the TAD carrier fabric areapproximately equal, or if the Fourdrinier wire is operating at arelatively slower speed than the TAD carrier fabric, then a relativelyhigh amount of fibers are distributed in the walls of the formedfeatures compared to the formed features of the prior art and arelatively bulky product may be achieved. In other embodiments, thespeed of the Fourdrinier wire is from about 0% to about −6% of the TADcarrier fabric (wire-to-press draw of from about 0% to about −6%). Oneof skill in the art will appreciate that a resin coated belt may be usedinstead of a TAD carrier fabric.

While this invention has been described with respect to at least oneembodiment, the present invention can be further modified within thespirit and scope of this disclosure. This application is thereforeintended to cover any variations, uses, or adaptations of the inventionusing its general principles. Further, this application is intended tocover such departures from the present disclosure as come within knownor customary practice in the art to which this invention pertains andwhich fall within the limits of the appended claims.

1. A fibrous web, comprising: a fibrous construct having at least oneformed surface feature, said surface feature including a topographicalpattern reflective of a weave pattern in a fabric used in a papermakingmachine having a through air drying (TAD) system, the fabric including:a single layer of yarns arranged in a repeating weave pattern, each saidweave pattern including: a plurality of warp yarns substantiallyoriented in a machine direction (MD) defining MD yarns; and a pluralityof weft yarns substantially oriented in a cross machine direction (CD)defining CD yarns, said MD yarns each having at least one long floatwithin said weave pattern, each said long float being adjacent at leastone other long float of an MD yarn, said weave pattern being a plainweave apart from said long floats.
 2. The fibrous web of claim 1,wherein within said weave pattern said long floats that are adjacent toeach other form at least one MD float pattern within said weave pattern.3. The fibrous web of claim 2, wherein within said weave pattern said atleast one MD float pattern is a plurality of MD float patterns.
 4. Thefibrous web of claim 3, wherein within said weave pattern said pluralityof MD float patterns are each one of identical and mirror imaged.
 5. Thefibrous web of claim 4, wherein within said weave pattern each of saidplurality of MD float patterns are surrounded with said plain weave. 6.The fibrous web of claim 4, wherein within said weave pattern each ofsaid plurality of MD float patterns touch each other forming acontinuous MD float pattern with said plain weave defining the balanceof said weave pattern.
 7. The fibrous web of claim 1, wherein withinsaid weave pattern each said long float floats across at least 3 CDyarns.
 8. The fibrous web of claim 7, wherein within said weave patterneach said long float floats across at least 4 CD yarns.
 9. The fibrousweb of claim 8, wherein within said weave pattern each said long floatfloats across at least 5 CD yarns.
 10. The fibrous web of claim 1,wherein the papermaking machine having a TAD system includes: adewatering fabric, a fibrous web is dewatered through the dewateringfabric, the dewatering fabric and said fabric being on opposite sides ofthe fibrous web; and a permeable belt in contact with a portion of thefabric, there being an airflow in a direction such that the airflowfirst passes through said permeable belt, then said fabric, then thefibrous web, then said dewatering fabric.
 11. A fibrous web obtainableby a process in a papermaking machine having a through-air dryer, theprocess comprising the steps of: discharging a fibrous slurry between aforming fabric and a structured fabric; and removing moisture from saidfibrous slurry through at least one of said forming fabric and saidstructured fabric to thereby form the fibrous web, said structuredfabric being a single layer structured fabric of yarns arranged in arepeating weave pattern, a fibrous web being formed between said formingfabric and said structured fabric, each said weave pattern including: aplurality of warp yarns substantially oriented in a machine direction(MD) defining MD yarns; and a plurality of weft yarns substantiallyoriented in a cross machine direction (CD) defining CD yarns, each ofsaid MD yarns having at least one long float within said weave pattern,each said long float being adjacent at least one other long float of anMD yarn, said weave pattern being a plain weave apart from said longfloats.
 12. The process of claim 11, wherein within said weave patternsaid long floats that are adjacent to each other form at least one MDfloat pattern within said weave pattern.
 13. The process of claim 12,wherein within said weave pattern said at least one MD float pattern isa plurality of MD float patterns.
 14. The process of claim 13, whereinwithin said weave pattern said plurality of MD float patterns are eachone of identical and mirror imaged.
 15. The process of claim 14, whereinwithin said weave pattern each of said plurality of MD float patternsare surrounded with said plain weave.
 16. The process of claim 14,wherein within said weave pattern each of said plurality of MD floatpatterns touch each other forming a continuous MD float pattern withsaid plain weave defining the balance of said weave pattern.
 17. Theprocess of claim 11, wherein within said weave pattern each said longfloat floats across at least 3 CD yarns.
 18. The process of claim 11,wherein the papermaking machine includes a permeable belt in contactwith a portion of said single layer structured fabric, the fibrous webbeing between said single layer structured fabric and said formingfabric, there being an airflow in a direction such that the airflowfirst passes through said permeable belt, then said single layerstructured fabric, then the fibrous web, then said forming fabric.
 19. Afibrous web obtainable by a process in a papermaking machine having athrough-air dryer, the process comprising the steps of: discharging afibrous slurry between a forming fabric and a structured fabric; andremoving moisture from said fibrous slurry through at least one of saidforming fabric and said structured fabric to thereby form the fibrousweb, the fibrous web having at least one surface feature, said surfacefeature including a topographical pattern reflective of a weave patternin said structured fabric used in a papermaking machine, said structuredfabric including a single layer of yarns arranged in a repeating weavepattern, each said weave pattern including: a plurality of warp yarnssubstantially oriented in a machine direction (MD) defining MD yarns;and a plurality of weft yarns substantially oriented in a cross machinedirection (CD) defining CD yarns, said MD yarns each having at least onelong float within said weave pattern, each said long float beingadjacent at least one other long float of an MD yarn, said weave patternbeing a plain weave apart from said long floats.
 20. The process ofclaim 19, wherein within said weave pattern said long floats that areadjacent to each other form at least one MD float pattern within saidweave pattern.